On a german website, somebody blogs about his impressions at the Berlin webOS connect event.

He says, that they were not told anything about the battery. But when he first looked at the demo-device, it was 50% battery. After 45 minutes of testing around with it (without videos or games, just standard apps, browsing, ...) it was at 41%.

So the battery seems to be at about 8.3 hours of run-time with pre-release hardware/software.

This would already suit all my needs, let alone if they still can tweak it a little bit on final hardware/software.

Great news, but you cant create a reliable estimate with that info because lithium ion batteries' performance changes as the percentage goes down. The first 10% percentage isn't good at all (thats why it seems like it dies so fast at the start), 85-60% has the best performance.

The awesome part about this though is that your estimate might be less than the actual battery life. Even if you hit it dead on, 8.5 hours is still great time for continual usage!